Abstract: An optical system for a laser level is described. The laser level includes at least two optical systems which are parallel to and oppositely adjoin to each other in a same plane. Each optical system includes a laser light source, a regular lens, a diffusion lens, a beam-splitting element, and an outer casing as well as the regular lens and the diffusion lens are located between the laser light source and the beam-splitting element. For the optical system of the laser level, the laser beam is sequentially regularized, diffused and split into a fan-shaped light beam with an angle greater than 180 degrees to ensure that the light beams from the optical systems are spread in the same plane. Thus, the laser level generates a disk-shaped light beam with 360 degrees to indicate a circular mark in the same plane.

Abstract: An optical system for a laser level is described. The laser level comprises at least two optical systems which are parallel to and oppositely adjoin to each other in a same plane. Each optical system comprises a laser light source, a regular lens, a diffusion lens, a beam-splitting element, and an outer casing as well as the regular lens and the diffusion lens are located between the laser light source and the beam-splitting element. For the optical system of the laser level, the laser beam is sequentially regularized, diffused and split into a fan-shaped light beam with an angle greater than 180 degrees to ensure that the light beams from the optical systems are spread in the same plane. Thus, the laser level generates a disk-shaped light beam with 360 degrees to indicate a circular mark in the same plane.

Abstract: A combination lock for suitcases, luggage and the like of a simplified construction has a knob with three positions: a locking position, an unlocking position and a third position for changing the combination code of the lock. In order to prevent undesired entry into the code-changing position, a blocking mechanism is provided which is conveniently mounted on the knob. Normally the blocking mechanism can prevent the knob from entering its code-changing position, and during the re-adjustment of the code, the blocking mechanism can retain the knob in its code changing position. The lock is further provided with a latch member which allows a corresponding flap or hook to be pressed into locking position regardless of whether or not the number wheels are correctly dialed.